In general, laser beam level instruments are used in the surveying and construction industries. They typically sweep (rotate) a laser beam in a horizontal plane. The laser beam is then detected by sensors or detectors to determine points level with the base point. The instruments are portable and self-contained.
The laser level is provided with a limited degree of self-leveling to maintain the laser beam in the horizontal plane. Automatic self-leveling makes initial set-up and adjustment of the laser level instrument faster since precise adjustments are not required for the initial set-up of the instrument.
Conventional laser leveling instruments accomplish self-leveling by aiming a stationary laser light source, such as a laser emitting diode, at a pendulated lens mounted below the light source. The pendulated lens moves under the force of gravity within the self-leveling range to position the lens so as to direct the light beam in a true vertical direction. The vertical beam is then deflected 90 degrees into a true horizontal beam by means of a prism or mirrors. Rotation of the prism or mirrors causes the beam to sweep a true horizontal plane, providing a precise leveling reference.
The present invention mounts the laser light source on a pendulous platform instead of on the stationary frame of the instrument.